Add 72/20 and 40/21
1st number: 3 12/20, 2nd number: 1 19/21
72/20 + 40/21 is 578/105.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
40/21 = 40 × 20/21 × 20 = 800/420 - Add the two like fractions:
1512/420 + 800/420 = 1512 + 800/420 = 2312/420 - 2312/420 simplified gives 578/105
- So, 72/20 + 40/21 = 578/105
In mixed form: 553/105
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